Little is known about the social and sexual network features of orphan and abandoned children (OAC), yet network differences may contribute to low educational attainment, inappropriate employment, and high-risk sexual behavior, and ultimately put OAC at risk for HIV infection. The long-term goal of this research is to de-termine key intervenable factors that contribute to OAC disadvantage or resilience, in order to construct viable interventions for promoting OAC health and well-being. The overall objective in this application is to assess OAC social and sexual network composition and variability, and determine how network features are asso-ciated with low education, income-generation, and HIV-risk behaviors. The central hypothesis for this work is that the social and sexual networks of OAC are small with low variability and these network features translate into reduced access to educational support, fewer positive employment opportunities and increased sexual risk-behavior. This hypothesis is based upon preliminary research suggesting variability in the size and hetero-geneity of OAC education- and employment-related networks. The central hypothesis will be tested by collect-ing and analyzing both social and sexual network data within the data collection infrastructure of an existing NIH-funded OAC cohort: the positive outcomes for orphans (POFO) study. POFO is in the first of its five-year continuation funding, which will allow this proposed research to collect longitudinal network and outcome data (at two time points). Aim #1a: identify the composition and variance social network characteristics of OAC, including educational and employment-related supports; and Aim #1b: identify the sexual net- work composition and variance characteristics of OAC, using a network analysis approach for both sub-aims. The working hypothesis for Aim 1 is that OAC's networks are small with limited variability. Aim #2: assess the association between the social network characteristics and health-related outcomes (edu- cation, income-generation) and between the sexual network characteristics and HIV-risk outcomes us- ing exponential random graphic models for network data. The working hypothesis for this aim is that OAC social and sexual network features are associated with low levels of success in staying in school, obtaining ap- propriate employment, and high sexual risk-behavior (e.g., age at sexual debut, number of sexual partners, characteristics of sexual partners). Completing the proposed research will impact the lives of OAC by: 1) estab- lishing if OAC network features account for success in educational, income generation, and sexual risk-taking behaviors; 2) providing the basis for interventions to mitigate damage done to OAC to prevent further disen- franchisement as OAC enter their adult lives, and 3) ensuring these OAC have the chance to achieve their full potential. Because this cohort of OAC are transitioning out of structured care settings into their adult lives, this work must be conducted now before they disappear within the context of poverty and disadvantage that cha- racterizes so many orphaned and abandoned children today. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because it promises to elucidate mechanisms from orphanhood and abandonment to life-long disadvantage in educational, employment and HIV risk-related domains. Thus, the proposed research is relevant to the part of NICHD's mission that pertains to optimizing all children's potential to achieve healthy and productive lives.